Development of Powder-in-Tube Processed Iron Pnictide Wires and Tapes

• Published in: IEEE transactions on applied superconductivity 2011-06, Vol.21 (3), p.2878-2881
• Main Authors: Ma, Yanwei, Wang, Lei, Qi, Yanpeng, Gao, Zhaoshun, Wang, Dongliang, Zhang, Xianping
• Format: Article
• Language: English
• Subjects: Addition; Ag sheath; Applied sciences; critical current; Electrical engineering. Electrical power engineering; Electromagnets; Electronics; Exact sciences and technology; Grain boundaries; grain connectivity; Iron; iron pnictides; Lead; Lead (metal); Materials; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Sheaths; Silver; Superconducting devices; Superconducting filaments and wires; Superconducting tapes; Superconductivity; Various equipment and components; Wire; Wires; wires and tapes
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2010.2079311

The development of PIT fabrication process of iron pnictide superconducting wires and tapes has been reviewed. Silver was found to be the best sheath material, since no reaction layer was observed between the silver sheath and the superconducting core. The grain connectivity of iron pnictide wires and tapes has been markedly improved by employing Ag or Pb as dopants. At present, critical current densities in excess of 3750 A/cm 2 (I c =37.5A) at 4.2 K have been achieved in Ag-sheathed SrKFeAs wires prepared with the above techniques, which is the highest value obtained in iron-based wires and tapes so far. Moreover, Ag-sheathed Sm-1111 superconducting tapes were successfully prepared by PIT method at temperatures as low as ~900°C, instead of commonly used temperatures of ~1200°C. These results demonstrate the feasibility of producing superconducting pnictide composite wires, even grain boundary properties require much more attention.